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Hubble diagram of gamma-ray bursts: Robust evidence for a Chaplygin gas expansion-driven universe with phase transition at $z \simeq 3$

Herman J. Mosquera Cuesta·Habib Dumet M.·Rodrigo Turcati·Carlos A. Bonilla Quintero·Cristina Furlanetto·Jefferson Morais
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Abstract

The Hubble diagram (HD) of Gamma-Ray Bursts (GRBs) having properly estimated redshifts is compared with the predicted one for the Chaplygin gas (CG), a dark energy candidate. The CG cosmology and that of Friedmann and $Λ$-CDM models are studied and confronted to the GRBs observations. The model-to-sample $χ^2$ statistical analysis indicates the CG model as the best fit. The present GRBs HD plot exhibits a marked trend: as one goes back in time, it gets much closer to the predict HD for a Friedmann universe. This clear trend conclusively demonstrates that a transition from decelerate to accelerate expansion did take place. However, contrarily to claims based on supernovae type Ia, the transition redshift lies somewhere between $\sim 2.5 < z \simeq 3.5$ rather than at $z \sim 0.5-1$. All of these striking features of the GRBs HD constitute the most robust demonstration that the Chaplygin gas can in fact be the universe's driving dark energy field.

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Herman J. Mosquera Cuesta, Habib Dumet M., Rodrigo Turcati, Carlos A. Bonilla Quintero, Cristina Furlanetto, Jefferson Morais. 2006-10-26. Hubble diagram of gamma-ray bursts: Robust evidence for a Chaplygin gas expansion-driven universe with phase transition at $z \simeq 3$. https://arxiv.org/abs/astro-ph/0610796

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